$xy + 3xz + 7x + 3 = -2y - 3$ Solve for $x$.
Answer: Combine constant terms on the right. $xy + 3xz + 7x + {3} = -2y - {3}$ $xy + 3xz + 7x = -2y - {6}$ Notice that all the terms on the left-hand side of the equation have $x$ in them. $1{x}y + 3{x}z + 7{x} = -2y - 6$ Factor out the $x$ ${x} \cdot \left( y + 3z + 7 \right) = -2y - 6$ Isolate the $x$ $x \cdot \left( {y + 3z + 7} \right) = -2y - 6$ $x = \dfrac{ -2y - 6 }{ {y + 3z + 7} }$